Skip to main content

Energy Manifold Natural Gradient Descent: From Riemannian Optimization to Modern Neuroscience, NeuroAI and Quantum Physics

Dr. Rishabh Pathak
When Geometry, Energy, Artificial Intelligence and Neuroscience Converge Modern Artificial Intelligence is rapidly moving beyond the idea that learning simply means minimizing an error function. Increasingly, researchers are asking a deeper question: what is the structure of the space in which learning takes place? This question becomes particularly important when the system being modelled is constrained, nonlinear, dynamic, or governed by physical principles. A recent work titled “Energy Manifold Natural Gradient Descent: Riemannian Optimization for Neural PDE Solvers” , by Zhangyong Liang and Huanhuan Gao, introduces Energy Manifold Natural Gradient Descent (EMNGD) , a mathematical framework that extends energy-based natural-gradient optimization from unconstrained Euclidean parameter spaces to constrained Riemannian parameter manifolds . At its core, the framework proposes a simple but powerful principle: An optimization algorithm should not only determine how to reduce error; it sh...
Post a Comment

Continuous Theta Burst Stimulation (cTBS)

Image
Dr. Rishabh Pathak

Continuous Theta Burst Stimulation (cTBS) is a specific protocol of repetitive transcranial magnetic stimulation (rTMS) that is used to modulate cortical excitability and induce neuroplastic changes in the brain. Here is a detailed explanation of Continuous Theta Burst Stimulation:


1.      Definition:

o   cTBS: Continuous Theta Burst Stimulation is a patterned form of rTMS that involves delivering bursts of magnetic pulses at a specific frequency and intensity over a continuous period of time to a targeted area of the brain. It is characterized by the application of theta-burst patterns of stimulation.

2.     Stimulation Parameters:

o   Theta Burst Pattern: The theta burst pattern consists of bursts of three pulses at 50 Hz repeated at a theta frequency (5 Hz). This pattern is delivered continuously over a specified duration, typically ranging from several seconds to minutes, depending on the research or clinical protocol.

o   Intensity and Duration: The intensity of cTBS is usually set as a percentage of the individual's resting motor threshold, ensuring that the stimulation is tailored to the specific cortical excitability of the target area. The duration of cTBS can vary based on the desired effects and experimental design.

3.     Mechanism of Action:

o   Inhibitory Effect: cTBS is primarily known for its inhibitory effects on cortical excitability. By delivering continuous theta burst patterns, the stimulation leads to a reduction in neuronal firing rates and synaptic transmission in the targeted brain region.

o   Long-Lasting Effects: cTBS has been shown to induce long-lasting changes in cortical excitability, with inhibitory effects persisting beyond the stimulation period. This ability to modulate neural activity and induce plastic changes makes cTBS a valuable tool for studying brain function and potential therapeutic applications.

4.    Applications:

o   Research: cTBS is widely used in research settings to investigate the role of inhibitory mechanisms in cortical function, neural plasticity, and motor learning. Researchers utilize cTBS to study the effects of cortical inhibition on cognitive processes, motor control, and sensory functions.

o Therapeutic Potential: In clinical applications, cTBS is being explored as a potential treatment strategy for neurological and psychiatric disorders. By modulating cortical excitability and neural networks, cTBS may offer therapeutic benefits for conditions such as depression, chronic pain, stroke recovery, and movement disorders.

5.     Clinical Studies:

o  Depression: cTBS has shown promise as a non-invasive treatment for depression, particularly in individuals who are resistant to traditional therapies. By targeting specific brain regions implicated in mood regulation, cTBS may help alleviate depressive symptoms and improve overall well-being.

o  Neurorehabilitation: In the field of neurorehabilitation, cTBS is being investigated as a potential adjunct therapy to enhance motor recovery following stroke, traumatic brain injury, or other neurological conditions. By modulating cortical plasticity, cTBS may facilitate motor relearning and functional recovery.

In summary, Continuous Theta Burst Stimulation is a specialized form of rTMS that exerts inhibitory effects on cortical excitability and induces long-lasting changes in neural activity. With applications in research and clinical settings, cTBS offers insights into brain function, neuroplasticity, and potential therapeutic interventions for a range of neurological and psychiatric disorders.

 

Categories:

Comments

Post a Comment

Popular posts from this blog

Review Settings of EEG

Dr. Rishabh Pathak
The review settings of an EEG recording refer to the parameters that can be adjusted to optimize the visualization and interpretation of electrical brain activity. Here is an overview of the key review settings in EEG analysis: 1.       Amplification (Gain/Sensitivity) : o Definition : Amplification, also known as gain or sensitivity, determines how much the electrical signals from the brain are amplified before being displayed on the EEG recording. o Measurement : Typically measured in microvolts per millimeter (μV/mm). o Impact : Adjusting the amplification setting can affect the visibility of high-amplitude and low-amplitude activity. High-amplitude activity may require vertical compression to fit within the display range, while low-amplitude activity may require lower sensitivity settings for better visualization. 2.      Frequency Filtering : o Bandpass : The frequency range within which EEG signals are analyzed. Common settings include ...
Post a Comment
Read more

Cancellous Bone

Dr. Rishabh Pathak
Cancellous bone, also known as trabecular or spongy bone, is the other main type of bone tissue found in the human skeleton alongside cortical bone. Cancellous bone has a porous and lattice-like structure, providing flexibility, shock absorption, and a site for hematopoiesis (blood cell formation). Here are key features and characteristics of cancellous bone: 1.     Structure : o     Trabeculae : Cancellous bone is composed of a network of thin, bony trabeculae that form an interconnected lattice structure. o     Bone Marrow : The spaces between trabeculae contain red bone marrow, which is involved in the production of blood cells (hematopoiesis). o     Less Compact : Cancellous bone is less dense and compact than cortical bone, with a higher surface area-to-volume ratio. 2.     Composition : o     Trabecular Bone : The trabeculae are made up of lamellae, osteocytes, and canaliculi similar to corti...
Post a Comment
Read more

Anatomical Classification of Bones

Dr. Rishabh Pathak
Bones in the human body can be classified into five main anatomical categories based on their shape and structure. These classifications provide insights into the functions and characteristics of different bone types. Here are the five anatomical classifications of bones: 1.     Long Bones : o     Description : Long bones are characterized by their elongated shape, with a shaft (diaphysis) and two expanded ends (epiphyses). o     Examples : Femur, humerus, radius, ulna, tibia, fibula. o     Function : Long bones provide support, leverage, and mobility. They are essential for body movement and weight-bearing activities. 2.     Short Bones : o     Description : Short bones are roughly cube-shaped or have a similar length and width, providing stability and support. o     Examples : Carpals (wrist bones), tarsals (ankle bones). o     Function : Short bones contribute to we...
Post a Comment
Read more

Translocation, Retention and Potential Neurological Lesion in The Brain and Following Nanoparticle Exposure

Dr. Rishabh Pathak
Translocation, retention, and potential neurological lesions in the brain following nanoparticle exposure are important considerations in nanotoxicology and neurotoxicology research. Here are some key points regarding the impact of nanoparticle exposure on the brain: 1.       Translocation to the Brain : o Nanoparticles can enter the brain through various routes, including systemic circulation, olfactory nerve pathways, and disrupted blood-brain barrier (BBB) integrity. o Factors such as nanoparticle size, surface properties, shape, and surface modifications influence their ability to cross biological barriers and reach the brain parenchyma. 2.      Retention in the Brain : o Once nanoparticles translocate to the brain, they may exhibit different retention times depending on their physicochemical properties and interactions with brain cells. o Nanoparticles can accumulate in specific brain regions, such as the olfactory bulb, hippocampus, and...
Post a Comment
Read more

Unrestricted Sampling

Dr. Rishabh Pathak
Unrestricted sampling, also known as simple random sampling, is a fundamental sampling technique where each element in the population has an equal and independent chance of being selected for the sample. In unrestricted sampling: 1.     Equal Probability of Selection : §   In simple random sampling, every element in the population has an equal probability of being chosen for the sample. This ensures that each unit is selected independently of other units, without any bias towards specific elements. 2.     Random Selection : §   The selection of sample elements is done randomly, without any systematic pattern or predetermined order. This randomness is essential to ensure that the sample is representative of the population and to minimize selection bias. 3.     Independence of Selection : §   Each selection is made independently of previous selections, meaning that the inclusion or exclusion of one element does not influence the ...
Post a Comment
Read more